Help Diagnosing Leaking Heater Core

[togles]

Can someone help me with a procedure to pressurize or vacuum test only my heater core? I think its got a leak because the prior owner bypassed the rear heat and the front heat. I just want to get the front heat back but want to make sure the thing is solid before i run all the hoses and coolant through it. If i just connect the pressure/vacuum to the top most heater core pipe on the passenger side, and plug the top most heater core pipe on the drivers side, that would be the correct way to accomplish this, correct? Also, my AC works great, so not sure if thats any indication that the heater core is good?

 

[MissahPapaJ]

I would find a suitable 3 way T fitting connect between the inlet and outlet of the core slowly fill the heater core up with water ( to purge air ) and find a way to adapt a pressure tester to just that core might take some time consuming finagling to mod the three way T to accept a pressure tester. On my Snap-on pressure tester I removed the stock hose between the pump and the cap adaptor to a smaller diameter hose and lengthened it for checking leaking EGR coolers in diesels. I’m imagining taking the pressure tester cap side off and just leaving the hose attached and modifying one of the T barbs to accept the pressure hose on the pressure tester. Fill the system in question with water with minimal air in system and pressurizing I’m thinking don’t pressurize past 10psi, I think I could take more pressure but if it’s got a good leak it’ll show up I’m thinking.
it kinda depends on what tools you have at you disposal really. There’s more than one way to skin a pole cat!! Best of luck. Not sure what the psi is on a garden hose but you may be able to adapt a garden hose to the inlet of the core turn on the hose low pressure till air is purged ( some times you need to go both ways to completely purge air ) then when air is purged cap one side and increase hose pressure. As this would likely be the easiest way I’m less in love with it due to uncontrolled variables like unknown Psi out of the hose as most houses have around 35-45 psi water pressure and the core is likely not designed for that pressure but if your careful not to over pressurize the core it might be fine.